Method of and apparatus for attaching slide fastener coupling chains to a flexible support

Abstract

A method of and a sewing machine for affixing a continuous chain of coupling members for a slide fastener to a flexible support, e.g. a garment or a tape to be applied to a garment, utilizes a fabric fed by a mechanism below the worktable and a presser foot with a feeder above the worktable which advances the coupling chain in a composite movement including up-and-down and back-and-forth components. According to the invention, at least one of the drives is adjustable so that the increment of the displacement of the respective member (fabric or coupling chain) can be varied to ensure that the two members are stitched together free from undulations or corrugations after the stitching operation or any subsequent treatment to which the product may be subjected.

I claim: 
     
       1. A method of securing a slide fastener coupling chain to a flexible support, comprising the steps of: (a) incrementally advancing said support past a stitching location;   (b) feeding said coupling chain to said support and said stitching location and incrementally advancing said coupling chain past said location;   (c) sewing said coupling chain to said support at said location by repeatedly passing a sewing needle between coupling heads of said chain and through said support at said location synchronously with the increment feeds of said support and said coupling chain; and   (d) controlling the displacement per increment of feed of at least one of said incremental feeds to ensure flat, corrugation-free contact of the coupling chain with the support to which it is stitched at least after washing or ironing treatment thereof.   
     
     
       2. The method defined in claim 1 wherein the displacement increment of said coupling chain feed is controlled. 
     
     
       3. The method defined in claim 2 wherein said support is advanced along a worktable past said location by a fabric-feed dog from below and said coupling chain is advanced above said support by engaging it with a transport foot, said method comprising imparting to said transport foot a composite up-and-down and back-and-forth movement. 
     
     
       4. The method defined in claim 3, further comprising the step of, upon attachment of a predetermined length of coupling chain to said support, severing said coupling chain from an incoming length thereof fed to said location. 
     
     
       5. The method defined in claim 4 wherein the displacement of said transport foot actuates a blade for cutting said coupling chain. 
     
     
       6. An apparatus for sewing a coupling chain to a flexible support comprising: a sewing machine table provided with a fabric-feed mechanism for advancing said support past a stitching location;   a sewing machine head overhanging said table and provided with reciprocatable needle bar displacing a needle through said support at said location in synchronism with said mechanism;   a biased presser foot mounted on said head and riding on said support at said location;   a transport foot on said presser foot engageable with a coupling chain for advancing same past said location for stitching of said coupling chain to said support by said needle;   a chain-feed mechanism synchronized with said needle bar for incrementally displacing said chain past said location; and     control means operatively connected to one of said mechanisms for varying the displacement increment thereof to ensure flat contact of said chain and said support upon the stitching of said chain to said support.   
     
     
       7. The apparatus defined in claim 6 wherein said transport foot is provided with formations engaging in said chain between coupling heads thereof. 
     
     
       8. The apparatus defined in claim 6 wherein said presser foot is formed with a lever having a blade and is swingable to engage and cut said chain, and means operable by said chain-feed mechanism for actuating said lever. 
     
     
       9. The apparatus defined in claim 8 wherein the last-mentioned means includes a reversible solenoid mounted on said head and having a bowden cable, a wedge member on said presser foot being formed with a pawl displaceable by said bowden cable, said chain-feed mechanism including a projection engageable with said pawl for displacing same to actuate said lever. 
     
     
       10. The apparatus defined in claim 8 wherein said chain-feed mechanism includes lever and linkage means for imparting a composite up-and-down and back-and-forth movement to said transport foot.